myclass.java

建议：此程序最好放到计算机上调试

public class MyClass{
class MyClass1{
int pro11;
double pro12;
}
class MyClass2 extends MyClass1{
 double pro12;
int pro21;

}
class MyClass3 extends MyClass2{
 int pro21;
double pro31;

}
public static void main(String[] args ){
  MyClass3 x=new MyClass3();
	x.pro11=55;
	x.pro12 =3.14;
	x.pro21 =77;
	x.pro31 = 3.1415926;
	System.out.println(x.pro21);
	System.out.println(x.pro31);
}
}